In general, the present invention relates to optical devices and, more particularly, to telescopic oculars.
A large variety of optical instruments and miniaturized optical devices are mounted on eyeglass frames or headbands and other supports worn over the head of the user. Such devices include telemicroscopic instruments, which are used for magnifying the work area during precision work, especially in elecronics, medical applications, and surgical operations. These instruments may incorporate one or two telescopic oculars. When a pair of telescopic oculars are used, the possibility of misalignment between the lines of sight of the oculars arises.
While human vision is not as sensitive to horizontal disparity, vertical disparity between the two lines of sight, known also as dipvergence, can cause eyestrain. Vertical disparity that exceeds 30 arc minutes can result in diplopia and cause headaches. For visual comfort, it is recommended that vertical disparity should not exceed 3.4 arc minutes.
There is a need for a simple and convenient mechanism to vertically adjust the lines of sight for optical instruments in small increments to reduce or eliminate vertical disparity.
The invention is directed to an adjusting device for use with a pair of telescopic oculars. The oculars are part of an optical mounting assembly that includes a housing in which two slide bars are mounted. The oculars are mounted on the slide bars through bosses and mounting screws. An adjusting set screw is threaded through a hole on each slide bar so that it can push against the boss of the ocular and cause a small rotation of the line of sight in the vertical plane. By tightening or loosening the set screw, the line of sight of each ocular can be adjusted incrementally in the vertical plane, so that the vertical disparity, or divergence, between the lines of sight of the oculars is minimized or eliminated. After the desired degree of adjustment is achieved, the corrected configuration of the ocular assembly may be secured by the selective application of adhesive.